Sprinkler systems and variable timing means

ABSTRACT

A programming system involving automatic water sprinkling in which one of a plurality of resistances is automatically selected for insertion in the RC (resistance-capacitance) frequencydetermining circuit of a relaxation oscillator. The oscillator after a time delay established by the selected resistance, causes a motor to rotate a plurality of selected switches, one of which selects a different resistance and another of which selects a different watering station. Manual override is provided. Means involving an On-Off-Repeat switch allows a selected watering station to correspondingly be (1) included once in the program, (2) excluded from the program or (3) included for a second time (repeat) without regard to particular time of day. Means are provided to prevent a watering operation at a station when the ground at that station is sufficiently moist.

United States Patent 3,392,350 7/1968 Griffin SPRINKLER SYSTEMS ANDVARIABLE TIMING MEANS 20 Claims, 3 Drawing Figs.

US. Cl 307/41, 307/283, 307/301, 331/46 int. CL. 1102i 3/14FieldotSeorch 331/177,

178,111 X,S2, 46 X,48; 328/130, 131; 307/293, 283, 38, 39, 40, 41, 301

References Cited UNlTED STATES PATENTS Primary Examiner-Herman .l.Hohauser Anorney- Lyon & Lyon ABSTRACT: A programming system involvingautomatic water sprinkling in which one of a plurality of resistances isautomatically selected for insertion in the RC (resistancecapacitance)frequency-determining circuit of a relaxation oscillator. The oscillatorafter a time delay established by the selected resistance, causes amotor to rotate a plurality of selected switches, one of which selects adifi'erent resistance and another of which selects a ditferent wateringstation. Manual override is provided. Means involving an On-Off-Repeatswitch allows a selected watering station to correspondingly be (1)included once in the program, (2) excluded from the program or (3)included for a second time (repeat) without regard to particular time ofday. Means are provided to prevent a watering operation at a stationwhen the ground at that station is sufficiently moist.

PATENIED SEPI 4 Ian 3 604 943 sum 2 [1F 3 PATENTED SEP14|97| SHEET 3 OF3 M N K w Y 6 m w 0 mum W em MA /w my M m SPRINKLER SYSTEMS AND VARIABLETIMING MEANS The present invention relates to improved means andtechniques useful in time-controlled programs, particularly so inautomatic water-sprinkling systems.

An object of the present invention is to provide an improved automaticwater-sprinkling system in which the sprinkler valves at a plurality ofstations or locations are selectively energized at various selectabletimes of the day within a 14 period and also with the duration of asprinkling event being selectable and adjustable.

Another object of the present invention is to provide an improvedsprinkling system of this character which is relatively simple,inexpensive, and foolproof in operation.

Another specific object of the present invention is to provide animproved sprinkling system in which the timing is effected, usingcharacteristics of a capacitor-charging circuit.

Another specific object of the present invention is to provide a systemof this character in which various stations may be selected for a repeatwatering performance during a watering cycle and watering initiatedwithout clock control, so as to have the advantage that the repeatperformance may be accomplished immediately upon selection without therequirement of having to wait for a clock motor to operate a switch.

Another specific object of the present invention is to provide animproved water system incorporating means for preventing a wateringoperation at a particular station when the ground is sufficiently moist.

Another specific object of the present invention is to provide improvedmeans and techniques whereby, for example, either one or more of 12 orof 18, or of 23 stations may be selected.

The features of the present invention, which are believed to be novel,are set forth with particularity in the appended claims. The inventionitself, both as to its organization and manner of operation, togetherwith other objects and advantages thereof, may be best understood byreference to the following description taken in connection with theaccompanying drawings in which:

FIG. 1 illustrates an arrangement of controls on a panel of apparatusembodying features of the present invention.

FIG. 2 illustrates in schematic form the apparatus illustrated in FIG. 1connected to a source of current and to solenoid valves for programmingthe flow of water to a corresponding watering station.

FIG. 3 illustrates a modified form of the invention.

While the description makes specific reference to a watering system, itwill be appreciated that the invention in its broader aspects isapplicable to programming systems generally, wherein means other thansolenoid valves are relected and energized for selectable times.

Referred to FIG. 1, the same shows a panel having mounted thereonvarious controls which are designated by corresponding numbers in FIG.2.

The discs 16 and 17 are driven by a clock motor 34 (FIG. 2) such thatthe disc 17 makes 1 revolution per 2 weeks. The disc 16 includes 23manually controllable switch elements 16A, any one of which may beselected for performing a control function at a corresponding hour ofthe day. It is noted that there is one blank space at 168, and thiscorresponds to 6 a.m. in the morning, which is considered to be thestart of the day for these particular purposes. The disc 17 likewiseincludes a series of manually controllable switch elements 17A, any oneof which may be selected to perform a control operation at the beginningof a corresponding day in a 2 interval. The switches 16A and 17A areindicated also in FIG. 2.

The panel in FIG. 1 includes also an On-Off Switch 13; a socalled modeof operation switch 14, having a manual position and an automaticposition; a moisture sensor switch having an off position, and also anon" position.

- The panel in FIG. 1 includes means associated with each of the 12different watering stations, and these stations are designated also inFIG. 1 by the numerals 142. A detailed description of the particularmeans at station I suffices also to describe like means at the otherstations 2-2. At station 1, there is two manually operated elements,namely a knob 1A and a three-position switch 13. Knob 1A serves toadjust a resistor to establish a time interval or time delay extendingfrom 2 to 60 minutes (1 hour), as indicated by the numerals 2-60. Theswitch 13 has an on" position, an of position, and a repeat" position.

The panel, FIG. 1, includes also a momentary type pushbutton switch 19for advancing the control to a different watering station. Also, thepanel includes an apertured portion through which numerals on a numeralwheel 18 is visible, the particular numeral being an indication of thecorresponding station which has been selected and which is in operation.

These controls and visual indicating means are clearly interrelated inthe accompanying description of FIG. 2, which now follows.

SOLENOID VALVE AND MOTOR OPERATION CIRCUITS It is assumed that the threemating plug-and-socket connectors Pl, S1; P2, S2; and P3, S3 areengaged, in which case the wires designated by the same letter areinterconnected. For example, when plug and socket P1, P2 are engaged,plug wire A is connected to socket wire A; plug wire B is connected tosocket wire B, etc.

In such case, it will be seen that the AC voltage source 30 is at alltimes connected to the primary winding 31 of the transformer 32 and alsoto the clock motor 33, whose armature 34 drives the hour disc 16 and daydisc 17 through suitable gearing such that hour disc 16 and day disc 17through suitable gearing such that hour disc 16, divided into 24segments, rotates one complete revolution per 24 hours, i.e., per day,

and that correspondingly, the day disc 17, divided into 14 segments,rotates one revolution per 14 days, i.e., per 2 weeks.

In those instances where the system requires operation of a pumpillustrated at 35 to pump water through pipe 36 to a sprinkler indicatedat 37, it is necessary to condition the pump control circuit for thatpurpose; and that is accomplished by energizing the pump start relay 40through a circuit presently described. It will be seen that the lowerterminal of relay coil 40 is connected to lead H, which extends throughplug and socket P2, S2, to one terminal of secondary winding 42, whichhas its other terminal connectable to the other terminal of relay coil40 through a circuit which includes in this order: circuit breaker 44,lead G extending through P2, S2; master switch 13A in its closedposition; day and hour microswitches 17A, 16A respectively operated uponrotation of corresponding day and hour discs 17, I6: moisture sensorswitch 15 (which is jumpered or short circuited when no moisture sensoris being used in this particular system); mode of operation switch 14Ain its Automatic or Auto position illustrated in FIG. 2; and droppingresistance 46 connected to such relay coil 40. As illustrated, moisturesensing means ISA, including in conventional manner a switch 15C, isconnected to leads P and R that extend to opposite terminals of thepanel switch 15. Switch 15C is automatically closed when the moisture ata ground station is sufficiently high.

Relay coil 40, when energized, causes three of its relay switches, 40A,40B, and 40C, to close. Closure of switch 40A short circuits leads C andD, thereby conditioning the pump 35 for operation; closure of relayswitch 403 permits the rectified DC voltage to be applied to the otherrelay coil 50, so as to be energized through a circuit which extends:from the upper terminal of secondary winding 52, through circuit breaker53; connected leads E of P2, S2; through master switch 138; throughdropping resistance 55 and rectifier 56 and output terminal 59A of bruteforce filter circuit 57, 58, 59, switch 408, and the upper terminal ofthe DC relay coil 50. The other or lower terminal of such coil 50 isconnected to the other output terminal 598 through silicon controlledrectifier 140, which is fired or rendered conductive after acontrollable time delay, as explained later.

The other relay switch 40C when closed serves to energize the mastervalve 90 by connecting such valve 90 to secondary winding 52 through acircuit which includes circuit breaker 53, interconnected leads E,master power switch 13, switch 40C, valve 90, and interconnected lead .1of plug-socket P2, S2.

Thus, it will be seen when relay coil 40 is energized and siliconrectifier 140 conducts, the relay coil 50 is energized.

The normally closed section of relay switch 50A serves to energize thestation or zone solenoid valves 92, 93, 94 by applying that voltagewhich appears across the series connected relay coil 40 and resistor 46,through the following path: via lead 96, the movable arm of switch 50A,the lead 99 which extends to the wiper arm of wafer switch 76, throughstationary contact 1 of switch 76, through the On-Off-Repeat switch 18,and through the interconnected leads K of P2, S2 through the valves 92,93, and 94, which are connected in parallel, and interconnected leads Hto the other terminal of relay coil 40 across which the energizingvoltage appears. Thus when silicon rectifier 140 remains nonconductive,i.e., relay coil 50 remains deenergized, the water control solenoidsselected by switch 76 may be energized to cause water to flow.

The normally open relay switch 508 is associated with the time delaycircuit and is connected thereto as follows: The fixed contact of switch50B is connected to lead 98, which may be considered to be at groundpotential. The movable contact of switch 50B is connected to oneterminal of resistance 95, having its other terminal connected tojunction point 96 with one terminal of resistance 102, 128, andcapacitors 100, 100A. The other terminal of each of capacitors 100, 100Ais connected via switch 148 in its Automatic" to the grounded lead 98and the other terminal of resistance 102 being connected via resistance1A and wafer switch 78 to the voltage source lead 94, so that in thedeenergized condition of relay coil 50, a charging circuit for capacitor100, 100A is established via resistance 102, and in the energizedcondition of relay coil 50, the precharged capacitor 100, 100A may bedischarged via resistor 95.

Also, when such relay coil is energized, the movable contact of thesingle-pole, single-throw switch 50A engages the lower stationarycontact to energize the motor winding 70 for driving cam 72 and itsassociated numeral wheel 18, selector switches 76, 78, and end cycleswitch 80. The coil 50 is energized after a time delay established inthe timing circuit or section.

THE TIMING SECTION The timing section involves two unijunctiontransistor relaxation oscillators 109, 119 which are continuouslyenergized by a rectified DC voltage which appears continuously betweenleads 94 and 98 when main power switch 13B is closed. The basicoperation of these relaxation oscillators involves the measurement oftime by the charging of a capacitor through a resistance. (RC circuit).At the time the capacitor has charged to a predetermined voltage, theunijunction switches on. The turning on of the unijunction can be usedto trigger other events as a result of a signal being generated. Also,the turning on of the unijunction transistor causes the timing capacitorto discharge through the base to emitter resistance of the transistor.The unijunction transistor then turns off and the capacitor again beginsits charging cycle.

More specifically, the first relaxation oscillator 109 involvestransistor 110, resistances 111 and 112, capacitor 114, and couplingcapacitor 116. Transistor 110 is a 22646-type unijunction transistor.Resistance 112 and capacitor 114 connected between voltage leads 94 and98 provide the RC timing circuit. Oscillator 109 functions to supply a%-volt negative pulse through capacitor 116 each time the transistor 110is rendered conductive. This pulse enables the second relaxationoscillator 119 to obtain a long, l-hour time delay when desired. Theoscillation rate of the first oscillator 109, measured in terms of itsRC time, is preferably less than 0.02 times that of the secondoscillator 119.

The second oscillator 119 involves transistor 120, resistances 121, 122,124, 102, 95, 128, diode 127, and capacitors A, 100 and one of theadjustable 10 megohm panel control resistances lA-12A depending uponwhich of such resistances is switched in by wafer switch 78. The la-voltnega tive pulse coupled to the second relaxation oscillator 119 viacapacitor 116, enables transistor 120 to fire on 1,000 times lesscurrent than would be required without this pulse. Transistor 120 is a2N2647 transistor. The RC timing circuit is formed by the selectedresistance 1A-12A, resistance 102, and capacitor 100A, 100. Even thoughtransistor 120 is turned off, there may be some leakage current flowingin the emitter of transistor 120. As this back current is temperaturedependent, it may vary at various times. To prevent this back currentfrom causing timing inaccuracies by also charging capacitor 100, 100A, acircuit including diode 127 and resistance 128 is provided. Resistorprovides bias for the diode 127. Resistance 121 allows for temperaturecompensation and a trim pot adjustment to compensate for componenttolerances in production. Resistor 124 has developed thereacross avoltage pulse, which is coupled to the silicon controlled rectifier(SCR) circuit whenever transistor 120 is rendered conductive.

The SCR circuit 140 involves rectifier 141, resistance 144, and therelay coil 50. When transistor 120 switches On," it results in a voltagebeing developed across resistance 124, which is coupled to the gate ofrectifier 141, which may be of the C6F type. When rectifier 141 fires asa result of this gate pulse, relay coil 50 is energized.

Once the rectifier is thus fired," i.e., gated on," it is turned off byreducing the anode voltage to 0 or by reducing the current flowingthrough the rectifier. Resistor 144 serves as a biasing resistor forrectifier 141.

OPERATION In operation, typically when the RC timing circuit of thesecond oscillator 119 has charged to the peak point firing potential oftransistor 120, it switches 0n" and causes a gate pulse to be suppliedto the rectifier 141; and when it fires, relay coil 50 is energized. Therelay switch 50A is operated to remove valve voltage from the valveoutput wafer switches 76, thereby providing some protection for thewafer contacts. This same set of relay contacts then supplies voltage tothe station selector motor 70, causing it to begin to drive. The indexcam 72 rotates, causing the index microswitch 60 to close. This switch60 parallels the rectifier 141 and reduces the rectifier current to 0and thus turns the rectifier Off." Also, such switch 60 maintains therelay coil 50 energized until the movable element of such indexingswitch falls into the notch on the cam 72 associated with the nextstation. The relay switch 50B provides an alternate discharge path forthe timing capacitor of transistor 120 through resistor 95 to ground.This assures that the capacitor is discharged to the same point eachtime. The circuit is then ready to begin another timing cycle for thenext station.

For these purposes, it will be seen that this motor winding 70, whenenergized causes the modified disc or indexing cam 72 to rotate to causethe movable arm of switch 60 to ride up a ramp and contact its matingstationary contact. There are 24 such equally spaced ramps on theindexing cam 72. In addition, the cam 72 has mechanically coupledthereto the 24- position numeral wheel 18, the so-called valve andrepeat wafer switch 76, the so-called station timing selector switch 78having 24 positions and also the so-called end cycle switch 80 which toohave 24 angular positions established by the cor responding 24 ramps onindexing cam 72. The indexing cam 72 and end cycle switch 80 are sooriented that when the switch arm 80A is in the notch as shown in FIG.2, the arm of switch 60 is on the raised portion of the index cam 72between positions 1 and 24.

It will be seen that the On-Off-Repeat switches 18, 23, etc. are eachindependently adjustable and are each of the doublepole, triple-throwtype. In the on" position of, for example, switch 18, watering at thecorresponding watering station occurs when the movable arm of waferswitch 76 engages its number 1 stationary contact. However, if thecontroller is to cycle through a station, for example, station 1, itsstation selector switch 18 is set to the off" or intermediate position,in which case it will be seen that the valve voltage is now switchedfrom the valves 92-94 to the station selector Enercon motor winding 70by that switch 1B in its assumed off position. Consequently, when thisoccurs, the wafer switch 76 does notstop at its number I position, butadvances to its number 2 position, corresponding to watering stationnumber 2, and stops at such number 2 position, providing however, thatthe ()n-Otf-Repeat switch 28 is in its on position or in its repeat"position. If switch 28 is in its off position, the motor winding 70 isagain energized and the wafer switch 76 is advanced to its number 3position. The motor 70 is deenergized only when the wafer switch 76 isadvanced to a position wherein a correspondingly numbered On-Off-Repeatswitch is either in its on position or in its repeat position. Thissocalled repeat position of any of the switches llB-IZB causes or allowswatering at a repeat selected watering station to occur twice during onerevolution of the end stop switch 80 prior to its movable contact 80Aentering the notched insulated portion of the conductive ring portion ofswitch 80. Thus, as illustrated in FIG. 2, switch 2B in its repeatposition supplies a valve voltage to lead L in either the number 2position of wafer switch 76 or in its number 14 position. Thus, beforeone complete cycle is completed, i.e., before the wafer disc 80 makesone complete revolution two watering events occur at watering stationnumber 2 when the wafer switch 76 is at rest in its number 2 and in itsnumber 14 positions. However, only one watering event occurs at stationI at which switch 13 is not in its repeat position but is in its on"position.

The pushbutton switch 19 on the panel (FIG. 1) termed the stationadvance switch, when pressed causes its switches 19A and 19B to beclosed. Switch 19A serves to short circuit a series comprising thetime-controlled switches, the moisture sensor switch 15, as well as themode switch 14A and to apply an energizing voltage directly to relaycoil 40 from one terminal of the main power switch 13A. The other switch19B serves to apply a voltage directly to the motor winding 70 from thefrom the same terminal of the main power switch 13A. Thus, themotor-driven cam 72 is advanced and continues to be advanced so long asthe pushbutton switch 19 is operated. However, if there is only amomentary closure of switch 19A, 19B, sufficiently long to advance themotor to a point where the switch 80 is closed, the relay coil 40continues to be energized even though switch 19A may be open. This is sobecause switches 19 and 80 are in parallel. Under this condition, sinceswitch 198 is assumed to be reopened, energization of the motor ismaintained by switch 60 which maintains energization of the DC relaywinding 50 to energize motor 70. Switch 60 maintains energization ofmotor 70 until the movable arm of switch 60 falls on the next notch ofcam 72, to reopen switch 60. Thereafter, after periodic time delays andsubsequent stepping of the motor disc 72, the switch 80 is restored toits open position, and this corresponds to the end of the completecycle. Once the end of the cycle is reached, i.e., the switch arm 80Aenters the notched portion of the conductive ring portion of the switch80, some positive action is required to short circuit or bypass switch80. To start the next cycle, this is accomplished by operating eitherthe station advance switch 19 or as a result of the day and hourswitches 17A and 16A becoming closed (assuming in this latter instancesthat the mode switch 14A is in its automatic position and either switchor switch 158 is closed).

In the automatic position of switch 14A, the control is, of course,sensitive to a particular day, a particular hour, as established byswitches 17A and 16A, and also by the condition of the moisture sensorswitch 158, when used. When switch 158 is used, the watering cycle isprevented from being initiated in the event that the moisture content atthe selected watering station is sufficient to have previously resultedin opening of switch 158. However, once the watering at a station hasbeen initiated, the condition of switch 15C is immaterial; because atthat time, it is short circuited by switch 80.

Thus, it will be seen that the l4-day selector pins provide manualchoice of watering schedules on every day, alternate days, or as seldomas once in fourteen days. Each such pin controls a 24-hour period,beginning at 6:00 am. The 23-- hour selector pins provide manual choiceof start of a watering cycle at any hour of the day or night (except6:00 a.m.). Additional watering cycles may be initiated throughout theday at any hour after a previous cycle has been completed by adjustmentof additional hour" starting pins. Each station has an individualstation selector switch to provide for programming the operation at thatstation. The on portion of switch 13 will result in watering during theautomatic cycle only. The off position of that switch 18 results in thatstation being omitted from the automatic and repeat watering cycles. Therepeat position results in watering during the automatic cycle and therepeat cycle. When the controller has completed the automatic wateringcycle, the controller searches through the stations again andsequentially waters again those stations corresponding to those stationswitches that are in their repeat position.

MODIFICATION IN FIG. 3

The circuit previously described provides for 12 watering stations. Themodification in FIG. 3 provides for a greater number of stations, forexample, either a total of 18 stations or 23 stations, and involves theuse of a latching relay and an additional cam-operated switch. Forcomparison purposes, elements in FIG. 3 corresponding to like elementsin FIG. 2 have the same reference numeral, raised, however, by 100. Newor additional elements in FIG. 3 are designated by reference numerals inthe 200 series; and these include a latching relay, having an actuatingcoil 201 and associated relay switches 201A, 2018, and 201C, and amotor-driven cam 203, and associated microswitch 203A actuated thereby,and a motor driven 24-position wafer switch 207, and an indicating lamp209. Further, in comparing FIGS. 2 and 3, it will be seen that the leadsat the left in FIG. 3 are intended to be connected to circuitry havingcorresponding leads Y. 94, T, X, V, E, W, 99, S, H, and G in convertingthe 12 station control illustrated in FIG. 2, to the 18 station controlillustrated in FIG. 3. Each of the wafer switches 176, 207, 178 are eachof the make-beforebreak type and each have 24 positions. The index camI72 has 24 positions as previously; and the cam 203 has only one notchedportion within which the movable arm of switch 203A may enter to allowswitch 203A to close, to thereby energize relay coil 201, which is thenconnected in a series circuit extending from lead H, through coil 201A,through switch 203A, through switch 180, through master power switch 113A, and lead G, it being also noted that the stationary contact ofswitch 203A is connected to lead Y. The switch 203A is operated once perrevolution of motor 172, and this occurs in position 24, correspondingto position 24 of wafer switches 176, 207, 180, and 178.

Relay switch 201A has its movable switch arm connected to lead 99, andits lower stationary contact connected to the wiper arm of wafer switch207, and its upper stationary contact connected to the wiper arm ofwafer switch 176. The spaced stationary contacts 176, 207 are connectedto corresponding On-Off-Repeat switches 1018, 1028, etc.

The relay switch 2018 has its movable arm connected to one terminal ofend stop switch 180 and also to lead G via master power switch 113, thestationary contact of switch 201B as well as the movable contact ofswitch 201C being connected to the other terminal of switch 180 and alsoto lead Y. The stationary contact of switch 201C is connected to oneterminal of indicating lamp 209, having its other terminal connected tolead H.

It will be seen from the foregoing, that when switch 203A closes, relaywinding 201 is energized. This switch 203A is operated before switch 180opens. When winding 201 is energized, the single-pole, double-throwswitch 201A serves to transfer the voltage on lead 99 from wafer switch176 to wafer switch 207. Closure of switch 2013 results in in shortcircuiting of switch 180 to thereby prevent current from beinginterrupted. Closure of switch 201C causes light 209 to be lit, tothereby indicate a repeat function is being performed.

It will be observed that stationary contacts 19-24 of each of waferswitches 176 and 207 are interconnected by a corresponding jumper 178A,207A so that the control as illustrated is intended to' accommodate only18 stations. For a maximum of 23 station operation, these jumpers areremoved; and the stationary contacts then, unconnected, are eachconnected to a corresponding element at stations 19-23 respectively.Switch 178 is wired to assure continuous energization of the relaxationoscillators for increased stability and reproducibility.

During the automatic operation, the watering stations are selected byswitch 176; but on the subsequent repeat operations, the wateringstations are selected by switch 207. The particular stations that areeffective, however, are established by the position of the correspondingOn-Off-Repeat switch as previously discussed in connection with FIG. 2.

We claim:

1. in a programming system, a relaxation network involving aresistance-capacitance circuit which establishes the timing of saidnetwork; a plurality of adjustable resistances, one of which may beselected for insertion in said network to correspondingly establish thetiming of said network; and switching means operated by said network inaccordance with its timing for sequential selection and insertion ofsaid adjustable resistances in said network.

2. A system as set forth in claim 1 wherein said network includes a pairof relaxation oscillators with the first of said oscillators serving inaccordance with its timing to trigger the other of said oscillators, anda selected one of said adjustable resistances serves as a frequencydetermining element of said other oscillator, and the oscillation rateof the first oscillator is greatly higher than the oscillation rate ofsaid other oscillator.

3. A system as set forth in claim 2 wherein each of said oscillatorsincludes a unijunction transistor whose conductance is controlled by aresistance-capacitance circuit.

4. A system as set forth in claim 1 including a source of voltage; aplurality of devices, one of which is selected for energization by saidswitching means.

5. A system as set forth in claim 4 in which three-position switchingmeans including an On position, an Off position, and a Repeat" positionis connected in series with a corresponding one of said devices, thefirst-mentioned switching means being sequentially operated from onestep to a succeeding step; said three-position switch in its On"position being effective to cause said first switching means to advanceonly one step and connect its corresponding series connected device;said three-position switch in its Off position being effective toprevent energization of its corresponding series connected device and tocause said switching means to advance to its next step; saidthree-position switch in its Repeat position being effective to causesaid first switching means to advance only one step and connect itscorresponding series connected device at two different times duringstepping of said first switching means during one of its cycles ofoperation.

6. A system as set forth in claim 5 in which said sequentially operatedswitching means includes a motor for advancing associated step-by-stepswitching means.

7. A system as set forth in claim 5 in which said motor drives aswitching device which makes one revolution per programming cycle.

8. A system as set forth in claim 5 in which said motor drives aswitching device which makes a plurality of revolutions per programmingcycle.

9. In a programming system of the character described, a source ofvoltage; a plurality of devices, one of which is selected forenergization by said source; step-by-step switching means sequentiallyoperated through a plurality of more than two steps during one cycle ofoperation a plurality of selector switch means having an On" position,an Off" position, and a Repeat position and being connected in serieswith a corresponding one of said devices; said selector switch in its Onposition being effective to connect said source to its correspondingdevice; said selector switch in its Off position being effective toprevent energization of its corresponding device; and said selectorswitch in its Repeat" position being effective to connect said source toits corresponding device twice during one cycle of operation of saidsequential operated switching means.

10. An arrangement as set forth in claim 9 wherein said sequentiallyoperated switching means includes a motordriven switching device thatmakes one revolution during each said cycle.

11. An arrangement as set forth in claim 10 in which said device makesmore than said one revolution during each said cycle.

12. A system as set forth in claim 5 including time clock operated meanseffective to initiate one of said cycles of operation, saidthree-position switch in its Repeat position being effective to causesaid sequentially operated switching means to advance only one step andconnect said source to a corresponding series connected device at twodifferent times during one cycle without requiring a second initiationby said time-clock-operated means.

13. A system as set forth in claim 9 including time-clockoperated meanseffective to initiate one of said cycles of operation, saidthree-position switch in its Repeat" position being effective to causesaid sequentially operated switching means to advance only one step andconnect said source to a corresponding series-connected device at twodifferent times during one cycle without requiring a second initiationby said time-clock-operated means.

14. in a programming system of the character described, a relaxationnetwork producing output pulses; a plurality of means for adjusting thetiming of said output pulses; and switching means receptive to andoperated by said network in accordance with only one individual outputpulse for sequential selection of said adjusting means such that eachoutput pulse produces a selection and a different timing of the nextsucceeding output pulse.

15. in a system of the character described, a relaxation networkincluding a timing circuit therefor which may be adjusted to adjust theperiodicity of pulses produced by said network; sequentially operatedswitching means operable sequentially to different positions;switch-operating means connected to said network for operating saidswitching means to different ones of its sequential positions inaccordance with each single pulse; and adjustable means connectable insaid timing circuit by said switching means for adjusting theperiodicity of each of said pulses and thereby said time duration.

16. In a system of the character described, a stepping device firstswitching means sequentially operated by said stepping device; aplurality of utilization devices one of which is selected by said firstswitching means; a relaxation network including a resistance-capacitancetiming circuit; a plurality of adjustable resistances, one of which maybe selected for insertion in said circuit to establish the timing ofsaid network; second switching means sequentially operated by saidstepping device and serving to connect a corresponding one of saidresistances in said circuit; and of means responsive to each pulseproduced by said network for advancing said stepping device and saidfirst and second switching means one step.

switch is connected in a series circuit which includes said source and atime-controlled switch.

19. A system as set forth in claim 18 in which said series circuitincludes also a moisture sensor switch 20. A system as set forth inclaim 18 in which another switch operated by said stepping device shuntssaid time-controlled switch.

1. In a programming system, a relaxation network involving aresistance-capacitance circuit which establishes the timing of saidnetwork; a plurality of adjustable resistances, one of which may beselected for insertion in said network to correspondingly establish thetiming of said network; and switching means operated by said network inaccordance with its timing for sequential selection and insertion ofsaid adjustable resistances in said network.
 2. A system as set forth inclaim 1 wherein said network includes a pair of relaxation oscillatorswith the first of said oscillators serving in accordance with its timingto trigger the other of said oscillators, and a selected one of saidadjustable resistances serves as a frequency determining element of saidother oscillator, and the oscillation rate of the first oscillator isgreatly higher than the oscillation rate of said other oscillator.
 3. Asystem as set forth in claim 2 wherein each of said oscillators includesa unijunction transistor whose conductance is controlled by aresistance-capacitance circuit.
 4. A system as set forth in claim 1including a source of voltage; a plurality of devices, one of which isselected for energization by said switching means.
 5. A system as setforth in claim 4 in which three-position switching means including an''''On'''' position, an ''''Off'''' position, and a ''''Repeat''''position is connected in series with a corresponding one of saiddevices, the first-mentioned switching means being sequentially operatedfrom one step to a succeeding step; said three-position switch in its''''On'''' position being effective to cause said first switching meansto advance only one step and connect its corresponding series connecteddevice; said three-position switch in its ''''Off'''' position beingeffective to prevent energization of its corresponding series connecteddevice and to cause said switching means to advance to its next step;said three-position switch in its ''''Repeat'''' position beingeffective to cause said first switching means to advance only one stepand connect its corresponding series connected device at two differenttimes during stepping of said first switching means during one of itscycles of operation.
 6. A system as set forth in claim 5 in which saidsequentially operated switching means includes a motor for advancingassociated step-by-step switching means.
 7. A system as set forth inclaim 5 in which said motor drives a switching device which makes onerevolution per programming cycle.
 8. A system as set forth in claim 5 inwhich said motor drives a switching device which makes a plurality ofrevolutions per programming cycle.
 9. In a programming system of thecharacter described, a source of voltage; a plurality of devices, one ofwhich is selected for energization by said source; step-by-stepswitching means sequentially operated through a plurality of more thantwo steps during one cycle of operation a plurality of selector switchmeans having an ''''On'''' position, an ''''Off'''' position, and a''''Repeat'''' position and being connected in series with acorresponding one of said devices; said selector switch in its''''On'''' position being effective to connect said source to itscorresponding device; said selector switch in its ''''Off'''' positionbeing effective to prevent energization of its correspondinG device; andsaid selector switch in its ''''Repeat'''' position being effective toconnect said source to its corresponding device twice during one cycleof operation of said sequential operated switching means.
 10. Anarrangement as set forth in claim 9 wherein said sequentially operatedswitching means includes a motor-driven switching device that makes onerevolution during each said cycle.
 11. An arrangement as set forth inclaim 10 in which said device makes more than said one revolution duringeach said cycle.
 12. A system as set forth in claim 5 including timeclock operated means effective to initiate one of said cycles ofoperation, said three-position switch in its ''''Repeat'''' positionbeing effective to cause said sequentially operated switching means toadvance only one step and connect said source to a corresponding seriesconnected device at two different times during one cycle withoutrequiring a second initiation by said time-clock-operated means.
 13. Asystem as set forth in claim 9 including time-clock-operated meanseffective to initiate one of said cycles of operation, saidthree-position switch in its ''''Repeat'''' position being effective tocause said sequentially operated switching means to advance only onestep and connect said source to a corresponding series-connected deviceat two different times during one cycle without requiring a secondinitiation by said time-clock-operated means.
 14. In a programmingsystem of the character described, a relaxation network producing outputpulses; a plurality of means for adjusting the timing of said outputpulses; and switching means receptive to and operated by said network inaccordance with only one individual output pulse for sequentialselection of said adjusting means such that each output pulse produces aselection and a different timing of the next succeeding output pulse.15. In a system of the character described, a relaxation networkincluding a timing circuit therefor which may be adjusted to adjust theperiodicity of pulses produced by said network; sequentially operatedswitching means operable sequentially to different positions;switch-operating means connected to said network for operating saidswitching means to different ones of its sequential positions inaccordance with each single pulse; and adjustable means connectable insaid timing circuit by said switching means for adjusting theperiodicity of each of said pulses and thereby said time duration. 16.In a system of the character described, a stepping device firstswitching means sequentially operated by said stepping device; aplurality of utilization devices one of which is selected by said firstswitching means; a relaxation network including a resistance-capacitancetiming circuit; a plurality of adjustable resistances, one of which maybe selected for insertion in said circuit to establish the timing ofsaid network; second switching means sequentially operated by saidstepping device and serving to connect a corresponding one of saidresistances in said circuit; and of means responsive to each pulseproduced by said network for advancing said stepping device and saidfirst and second switching means one step.
 17. A system as set forth inclaim 16 including third switching means operated by said steppingdevice; said pulse responsive means including a controlled rectifierconnected in series with a relay coil having an associated relay switch;said third switching means being shunt with said controlled rectifier; asource of voltage; and said relay switch serving to connect said sourceto said stepping device.
 18. A system as set forth in claim 17 in whichsaid relay switch is connected in a series circuit which includes saidsource and a time-controlled switch.
 19. A system as set forth in claim18 in which said series circuit includes also a moisture sensor switch.20. A system as set forth in claim 18 in which another switch operatedby said stepping device shunts said time-controlled switch.